.app-header {
  display: flex;
  background-color: #000;
  color: #fff;
  align-items: center;
}

.app-header .app-header-logo {
 display: block;
 margin-left: 20px;
 margin-right: 20px;
}

.app-content{
  padding: 20px;
  box-sizing: border-box;
}